Rotary sand spreader



March 13, 1956 F. E. UNDERWOOD 2,738,195

ROTARY SAND SPREADER Filed Feb. 17, 195] 4 Sheets-Sheet l 4 $heets-$heet 2 March 13, 1956 F. E. UNDERWOOD ROTARY SAND SPREADER Filed Feb. 17, 1951 V frweniar fiezaei'waud 9% WW;

March 13, 195 6 F. E. UNDERWOOD 2,738,195

ROTARY SAND SPREADER Filed Febi-IY, 1951 4 Sheets-Sheet 3 frzverziar j'm' Zywrzmad wmw r m Mar h 13, 1956 ,F. E. UNDERWOOD 2,738,195

ROTARY SAND SPREADER Filed Feb. 17. 1951 4 SheetsSheet 4 I I Hr [Mania 7' fim raierwaad Unit S ws ate t 2,738,195- ROTARY SAND SPREADER Frank E Underwood, Newton, Mass., assignor to Underwood Machinery Company, Boston, Mass., :1 corporation of Massachusetts Application February 17, 1951, Serial No. 211, {93

5 Claims. 01. 275-8) This invention relates to apparatus for spreading sand on highways and airport runways and has for its principal objects to provide improved apparatus which may be mounted on a truck chassis and which when moved along a highway or other place which is to be sanded will project sand at a considerable distance from opposite sides thereof to provide a very uniform blanket of sand over wide areas at opposite sides of the path of travel, which will blanket the intermediate area close to and beneath the apparatus and which can be adjusted to vary both the extent and thickness of coverage. Other objects are to provide an apparatus in which the operating parts will be subjected to a minimum of abrasion and are'so associated as to minimize jamming and breaking by reason of the presence of stones and other foreign matter in the sand, in which there is provision for quickly adjusting the parts to compensate for wear, in which the worn-out part may be quickly removed and replaced without substantial dismantling of the spreader mechanism or removal thereof from the truck chassis, and which will be rugged and durable.

In accordance with the foregoing objects the apparatus has a sand impeller rotatable about a substantially horizontal axis from which projects sand-engaging elements, the surfaces of which face in the direction of rotation, and a tray situated below the impeller con centric with the path of rotation of the extremities of the sand-engaging elements through which they move and sweep sand deposited on the surface of the tray laterally therefrom in a relatively high trajectory. The distance between the extremities of the sand-engaging elements and the surface of the tray is adjustable within predetermined limits so that each time one of the sand= engaging elements moves along the tray it may be brought close enoughto sweep the "entire layer of sand therefrom or only a portion thereof. To secure uniform spread at a maximum distance the speedof the impeller must be not only very high but unvarying since very small variations in speed will-be reflected in bare spots along the path of the spread which cannot be tolerated. Accordingly the impeller 1s weighted preferably near its rim 'sufiiciently so that irregularity in the delivery of the sand to the tray, congealed lumps of moist sand and/or stones which may be present in the sand will have no noticeable effect on the speed of the impeller.

There are two of'the foregoing impellers arranged one ahead of the other, rotating in opposite directions to eje'ctsand laterally at opposite sides of the machine, and each has a tray and is supplied with sand from a common hopper situated above the tray. The aforesaid sand-ejecting elements are primarily for delivering the sand laterally at a considerable distance from the opposite sides of the machine, and hence there are other secondary sand-engaging elements carried by each impeller to eject sand at lesser distances to fill in the area between the far flung sand and sides of the apparatus J Patented Mar. 13,1956

and also the area immediately beneath the machine. As illustrated, this means has surfaces inclined at an angle to the direction of rotation to cause projection of the sand laterally from the tray and also transversely thereof over one edge, the latter being left open to permit the sandjto be ejected therefrom.

The two impellers rotate in opposite directions so that sand acted upon by one is propelled toward one side of the apparatus and the other propelled at the opposite side. The open sides of the trays face each other, hence the sand from one is thrown forwardly and from the other rearwardly with respect to the direction of movement of the machine, thus affording a complete coveragean imperforate disk ismounted close to one wall and the clearance between its rim and the enclosing housing is kept as small as possible. The sand-ejecting elements extend transversely from the disk over the tray toward the opposite end wall. The disk portion serves in the capacity of a fly wheel, as heretofore indicated, and its rim is close enough to the peripheral wall of the housing to exclude sand and foreign matter from entering between it and the end wall.

The sand is delivered to each tray by a chute connected at its upper end to a hopper and inclined toward the face of the impeller disk with its delivery end at about the center of rotation of the impeller so that the sand flowing therefrom impinges upon the face of the disk as it falls into the tray. As located the sand is delivered from a side of the impeller into the path of the sand ejecting elements in the third quarter of rotation of the impeller and is discharged from the tray in the fourth ments are semi-cylindrical and flat, and the elements are attached to the disk so that the axis of the center of curvature of the semi-cylindrical surface is parallel to the plane of the disk and the plane of the flat surface is inclined thereto. The elements having the flat surfaces are situated inwardly of the elements having the semi cylindrical surfaces and on opposite impellers are inclined in opposite directions, that is, toward each other. There may be one or more of each of the semi-cylindrical and flat sand-engaging elements attached to each disk and as indicated they are located at different radial distances from the center of rotation.

The invention will now be described in detail with reference to the accompanying drawings in which:

Fig. 1 is 'aplan view of a sand hopper of the type with which my improved sand spreading means may conveniently be employed;

Fig. 2 is an elevation of one side of the sand hopper showing my improved sand spreading means depending from the rear end thereof;

Fig. 3 is a section on the line 33 of Fig. 5, with certain parts omitted, showing the two delivery chutes for delivering sand to the spreaders; v

Fig. 4 is an elevation at the rear end of the sand hop per, as seen from the right side of Fig. 2, showing the driving means for the sand conveyor in the sand hopper; Fig. 5 is a plan view, partly in section, looking down Fig. 4 at the rear on the sand spreading means shown in end thereof;

Fig. 6 is a detail of the sand-ejecting elements;

' Fig. 7 is a vertical section, on the line 7-7 of Fig. 5, looking toward the rear;

Fig. 8 is a longitudinal section on the line 88 of Fig. as seen from the right Side thereof; and

Fig. 9 is an isometric view of the impeller showing the sand-ejecting elements fast thereto.

Referring to Figs. 1, 2 and 4, there is shown a sand hopper 10 which is of relatively large capacity having inclined side and end walls 12 and 14, respectively, and a U-shaped bottom wall 16, Fig. 4, the ends of which project at 18 and 20 from the opposite end walls 14 of the hopper, as shown in Fig. 2. Transverse and longitudinal tie beams 22, disposed between the walls, join and reinforce the side and end walls at the top thereof. Braces 24, which are fixed at their lower ends to spaced parallel channel beams 26, Fig. 4, at the bottom of the hopper, support and reinforce the side walls in their inclined position. The channel beams 26 are joined at their opposite ends to form a rigid rectangular frame which provides the main support for the hopper as a whole, and is adapted to be removably fastened to the chassis of a trailer truck. In the U-shaped portion 16 of the hopper there are disposed a pair of parallel shafts 28 which are journaled at their opposite ends in suitable bearings formed in the end walls of the U-shaped bottom portion, the projecting portions of which are closed at the top and ends. Each shaft has on it a plurality of spaced blades 30 for pushing sand rearwardly along the bottom of the hopper for delivery through an opening 31 formed in the U-shaped bottom portion near its terminal end 33 to sand-spreading means 32. The shafts 28 are driven in opposite directions by means of meshing gears 34 fixed to their forward ends and a sprocket 36 fixed to one of the shafts which is connected by way of a chain 38, Fig. 4, to a sprocket 40 connected by way of a gear reduction unit and clutch 41 to the drive shaft of an engine 42 mounted laterally of the hopper at the forward end thereof on a horizontal, laterally extending frame 44 bolted to the under side of the supporting frame for the hopper.

According to the present invention, the sand-spreading means 32 which, as heretofore stated, is located at the rear end of the hopper, is supported below the rearwardly extending portion 18 of the U-shaped bottom 16 of the hopper by bolts 46, Fig. 2, passing through and secured to horizontal plates 47 welded to the under side of the beams 26 and comprises spaced forwardly and rearwardly disposed impellers 48 and 50, Fig. 8, mounted for rotation about horizontal axes on shafts 52 and 54. It is to be understood that the axes may be varied somewhat from the horizontal; however, for best results, they are more nearly horizontal than vertical. The shafts 52 and 54 are aligned end to end and journaled, at one end in vertical walls 56 and 58 and at their opposite ends in bearing members 53, supported by transversely extending beams 55. The walls 56 and 58 form, together with spaced parallel walls 60 and 62 and curved walls 64 and 66, substantially semi-cylindrical hoods 63 and 65 which house the upper portions of the impellers. The walls 60 and 62 extend vertically upward beyond the eurved walls 64 and 66, and have extending between them spaced parallel end walls 68, Fig. 3, and adjacent intermediatewalls 70 to form two hollow chutes of substantially rectangular cross-section located between the housings having oppositely inclined bottom walls 72, and 74, Figs. 2 and 8, arranged to deliver sand to the respective housings at about the center of rotation of the impellers through openings 76 and 78, Fig. 4, formed therein. The openings 76 and 78 (Figs. 3 and 8) are-each located at the side of the housing wherein the'impeller disk is moving downwardly so that sand delivered thereto through the opening is bound to impinge upon the downwardly movingportion of the disk and is therefore eonfined exclusively to the w r t qu of. ro a o of t e disk- By introd e ing the sand from the side of the impeller rather than into the p riph ry th r f a at th lowe hi d. q a e of rotation of the impeller the sand is operated upon by downwardly moving parts which confine it to the lower part of the casing and tray thus preventing it from being flung upwardly into the top part of the casing where small stones and other foreign matter included in the sand might become wedged between the impeller and the casing and by reason of their size and violence of movement damage the casing and the adjustment between the impeller and tray. Laterally extending flanges 80, Fig. 8, are fixed to the walls 60, 62, and 68 near the upper ends of the chutes, and are provided with apertures, Fig. 5, through which the bolts 46 are passed and by which the housings and impellers are bolted to the plates 47 below the opening 31. In that portion of the walls 60 and 62 which extend above the curved walls 64 and 66 and between the walls 70, Fig. 3, there is journaled a horizontal shaft 82 having on one end a sprocket 84 which is driven from a sprocket 86, Fig. 2, afiixed to the rear end of one of the shafts 28 by a chain 88, Fig. 4, Which passes over the sprocket 86 beneath the sprocket 84 over an idle sprocket 90 under a sprocket 92 fixed to the shaft 52 and back to the sprocket 86. As a result, rotational movement is imparted to the shaft 82 in one direction and to the shaft 52 in the opposite direction. At the opposite end of the shaft 82 there is fixed a sprocket 94, and rotational movement is transmitted to the shaft 54 from this sprocket by way of an idle sprocket 96, Fig. 7, and a sprocket 98 fixed to the shaft 54 over which passes. a chain 190. As thus driven, the shafts 52 and 54 are rotated in opposite directions. The sprockets and chains are enclosed in housings 102 and 104 fastened to the outer surfaces of the walls 56 and 58, respectively.

The impellers 48 and 50, Fig. 8, comprise disk-like members to which are attached laterally projecting sandengaging elements or blades. The impellers are fixed to the shafts 52 and 54 closely adjacent to the walls 56 and S8 of the chambers which house them, and there are disposed below these impellers trays 106 and 108 which are substantially concavo-convex in shape and which are fastened at such a heightwise position with respect to the disks that their inner surfaces clear the peripheral edges of the disks and the paths of movement of the sand-engaging elements are substantially concentric therewith. The trays extend forwardly and rearwardly from the walls and are about the same width as the width of the chambers 63 and 65 which house the upper portions of the disks. Each tray is adjustably supported, as shown for example with respect to the tray 108, Fig. 7, by threaded bolts 110 and 112, the former extending through a horizontal flange 113 formed at the lower edge of the curved wall 66 and retained therein by nuts 114 and the latter passing through a flange 116 formed on the wall 58 and being retained therein by a nut 118. The aforesaid threaded bolts 110 and 112 are so situated that rotation of the nuts 114 and 118 will draw the trays upward and concentrically with respect to the disks to take up wear which may occur. By adjusting the clearance between the trays and the impellers so that the entire thickness of the sand resting on the trays at any given time will be swept off by the passage of the impeller over the trays and by maintaining this spacing a maximum velocity may be imparted to the sand. If the spaces are allowed to become large by wear or improper adjustment, some of the sand will not be swept along and will form a drag on the overlying sand which will materially lessen the speed which the sand will attain as it is being swept from the tray and hence the spread. By varying the adjustment of the tray the amount of sand and the distance to which it is projected may be varied. Each tray, as will be seen, by reference to Fig. 7, extends peripherally of the impeller from the lower edge of the curved wall to which it is attached at one side of its housing downwardly, under the lowermost point of the disk and terminates laterally of the lowermost point in the fourth quarter of rotation of the impeller to provide a lateral opening'or gap 120 in the lower fourth of the path of rotation of the impeller. The tray at its terminal end is slightly upwardly curved and forms a launching platform from which thesand may be swept in a high are and in a lateral direction. The openings 120 in the respective housings are at opposite sides of the hopper.

Each of the impeller disks 48 and 50 has fixed to it and diametrically opposite thereof pairs of sand-engaging ejector elements or blades 122 and 124, Figs. 6 and 9. The element 122 has a semi-cylindrical surface 126, and the element 124 has a flat surface 128, the surfaces 126 and 128 being so situated that they face in the direction of rotation of the impeller disks. The disks are made heavy enough so that they function as flywheels, and when the impellers are brought up to their normal speed, the mo-' mentum of the disks smooths out uneven rotation of the impellers due to intermittent and uneven flow of sand for the hopper as may be caused bydampness, congealing, etc., and hence results in a more even distribution of the sand. Since the ejectors are fastened to each disk, they move with it and the latter serve to impart movement to the sand, act as baflies to prevent impingement of the sand on the walls of the housings, thereby reducing wear and preventing lodging of stones and other foreign material between the ejectors and the walls of the housings.

The semi-cylindrical surfaces 126 of the elements 122 extend laterally from the surface of the disks over the trays, and the axes of their centers of curvature lie parallel to the plane of the disks. As each disk rotates the semi-cylindrical surfaces act as scoops which catch some of the falling sandwithin the housing to which it is de liveredbefore it reaches the tray at the bottom of the housing, and also scoop up sand that is already deposited in the tray and'eject it laterally through the opening 120. As'illustrated, one impeller ejects sand from one side of theLap aratus and the other ejects sand at the opposite side; and, since the impellers are rotating at a high rate of speed, the sand is thrown in opposite directions in high arcs laterally at some distance from the vehicle, thereby to form broad bands of sand at opposite sides of the area being traversed.

The fiat surfaces 128 of the elements 124, however, are inclined with respect to the disks specifically from the surfaces of the disks inwardly toward the axis of rotation and at approximately 45, although the angle may vary from to 60 in accordance with what will best serve the purpose. These elements, being located radially inward of the elements 122, do not impinge upon the sand in the trays but rather intercept falling sand as it is delivered from the aforementioned chutes, giving it a swiping sort of impact which ejects it both laterally and away from the face of the disks, that is, widthwise of the trays but at a much less distance than the elements 122. The inclination of the flat surfaces 128 of the elements 124 are in opposite directions on their respective impellers so that sand is thrown rearwardly from the forward impeller and forward from the rear impeller. This throwing of the sand laterally and longitudinally lays down a band of sand close to the apparatus which fills in the space or gap between it and the sand thrown laterally and at a greater distance at opposite sides of the vehicle by the elements 122. The transversely thrown sand provides a good covering of sand below the apparatus, that is, between the wheels. Some additional sand is spilled over the open edges of the trays onto the area beneath the apparatus.

At opposite sides of the sand-spreading means there are mounted above the openings 120 deflector plates 130 which, as shown in Fig. 4, occupy a substantially horizontal position but which may be adjusted to take up any desired angular position. The deflector plates are mounted on brackets 132 fastened to the respective housings having spaced arms 134 terminating in apertured hubs 136. Bolts 138 are passed through the apertures in the hubs 136 and provide pivotal support for the inner ends of the deflector plates 130 which have formed integral therewith spaced apertured ears 140 through which the bolts 138 may be passed. HA nut 142 threaded on one end of each bolt 138 provides means for frictionally engaging the hubs and ears to maintain the deflector plates in a given position of adjustment. b

It is apparent that thesand-cngaging elements and the tray will receive most of the wear because of their relative movement and their direct contact with the sand, hence these parts may have to be replaced at intervals. Due to the construction of the spreading mechanism, how ever the parts may readily be removed and replaced with the minimum of manipulation. The tray is removable merely by backing off the nuts 114 and 118 and when these are removed access may be had to the sand-engaging elements by rotating the disk to bring them below the housing. These may then be detached by removing the bolts which fix them to the disk.

From the above description of the sandingapparatus illustrated herein it is evident that sand placed in the hopper 10 is delivered by power-rotated paddles 30 along .thebottom of the hopper to the rear portion thereof where it falls into two vertical-chutes 72 and 74 having oppositely inclined lower walls which direct the falling sand to substantiallythe central. portions of a pair of oppositely disposed spaced housings 63 and 65 within which there are mounted impeller members 48 and 50. Sand-ejecting elements 122 are so arranged that sand is ejected by them laterally at one side of the hopper from one impeller and laterally at the other side of the hopper from the opposite impeller to lay down strips of sand at opposite sides of the apparatus. ,The sand-ejecting elements 124' eject sand laterally but less distant and forwardly and rearwardly from the impellers toward each other to fill in the. areas not covered by the sand ejected from the ejecting elements 122. I

The extraordinarily wide spread secured with this apparatus feet at each side of the apparatus, as compared to prior apparatus having a maximum spread of approximately 35 to 50 feet) is attributed to a number of features, the principal of which is to employ constantly rotating impellers which travel at very high rotational speed in one direction in contrast to reciprocating impellers, and to impellers which rotate about horizontal axes in vertical planes in contrast to impellers which rotate about vertical axes is horizontal planes. Other features which improve the operation are derived from rotating the impellers in directions such that the sand leaves them in upwardly inclined paths rather than horizontal paths or downwardly inclined paths, attaching the sandengaging elements to disks which rotate with them thereby substantially eliminating friction between the sand and the enclosing housing, keeping the clearance between the disks and the housings very small so that stones cannot wedge between them, weighting the rims of the impellers so that their rotational speed remains substantially constant regardless of irregularities in the delivery of sand thereto or to the presence of congealed lumps of sand and/or foreign matter such as stones, keeping the clearance between the impellers and the trays at a minimum and adjusting this clearance so as to take up for wear.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims. It should also be understood that the apparatus may be used for spreading materials other than sand, e. g. salt, chemicals, crushed stone, gravel, fertilizer, and other materials and substances to be spread uniformly over an area.

I claim:

1. In a device for spreading sand, an impeller rotatable about a given horizontal axis, said impeller comprising a disk having semicylindrical and flat surfaces distributed uniformly about one face of said .disk' adjacent the periphery thereof facing in the direction of rotation, the axes of the center of curvature of said semicylindrical surfaces being parallel to a plane normal to the axis of rotation and the planes of the flat surfaces being inclined thereto, means for supplying sand to the impeller, and means for effecting rotation thereof.

2. In an apparatus for spreading sand, an impeller disk rotatable about a given horizontal axis, sand ejecting elements distributed uniformly around one face of said disk adjacent the periphery thereof for rotation of the ejector elements in a circular path comprising a lower quarter in which said elements are traveling downwardlyand a succeeding lower quarter in which said elements are traveling upwardly; the plane of which .is perpendicular to the axis of rotation, a tray concentric with the lower part of the impeller and extending along said first mentioned lower quarter of the path of rotation of the impeller and a part of said succeeding-lower quarter and terminating in said latter quarter so as to form an upwardly inclined shelf for receiving sand delivered to the impeller, means for supporting the tray in said position, means for delivering sand to the impeller from one side thereof within said first mentioned lower quarter of the path of rotation, and means for adjusting the tray to and from the path of the ejector elements carried by the impeller to vary the thickness of the sand on the tray. 3. In an apparatus for spreading sand, an impeller disk rotatable about a given horizontal axis, sand ejecting ele-' ments distributed uniformly around one face of said disk adjacent the periphery thereof for rotation in a plane perpendicular tothe axis-of rotation, means supporting a tray concentric with the lower part of the impeller and extending along a lower quarter of the path of rotation of the impeller and a part of the succeeding lower quarter and terminating in the latter quarter so as to form an upwardly'inclined shelf for receiving sand delivered to the impeller, and means for delivering sand to the impeller from a side thereofwithin said first mentioned lower quarter of the path of rotation, said first means being constructed and arranged to permit movement of the discharge end of the tray to and from the impeller disk thereby to vary the thickness of the sand on the tray at the place where the ejecting elements leave the tray.

4. A device according to claim 1 further characterized in that said semi-cylindrical and flat surfaces are located at different radial distances from the center of rotation so that the semi-cylindrical surfaces travel in one path and the fiat surfaces travel in another path.

5. Apparatus according to claim 2 further characterized by an inlet in said first mentioned lower quarter through which sand may be delivered to the impeller elements and an outlet in said succeeding lower quarter through which sand acted upon by the impeller elements may be discharged from the impeller elements.

References Cited in the file of this patent UNITED STATES PATENTS 186,410 ,Buist et a1. Jan. 23, 1877 1,000,004 Huber Aug. 8, 1-911 1,440,429 Williams Jan. 2, 1923 11,498,086 Ford June 17, 1924 1,616,303 Campbell Feb. 1, 1927 2,092,102 Wilson Sept. 7, 1937 2,170,360 Whelan Aug. 22, 1939 2,200,165 .Eulkerson et a1. May 7, 1940 2,281,212 Stoltzfus Apr. 28, 1942" 2,327,893 Hobson Aug. 24, .1943 2,430,020 Johnson Nov, 4, .1947 2,487,552 Humphrey Nov. 8, 1949 2,602,670 Burkart July 8, 1952v 2,645,500 M0ss July 14, 1953 FOREIGN PATENTS 345,992 Great Britain Mar. 27, 1931 560,687 Great Britain Apr. 14, 1944 597,224 Great Britain Jan. 24, 1948 

